1. Field of the Invention
The present invention relates to a manufacturing method for a semiconductor device and more particularly, to a manufacturing method for a semiconductor device using, as a capacitance film of a capacitor of a memory cell, a Ta2O5 film which is a dielectric having a high dielectric constant.
2. Description of the Related Art
With the increase of integration density of a DRAM (Dynamic Random-Access Memory) which is a kind of semiconductor memory devices, it has been studied to use a Ta2O5 film having a high dielectric constant, as a capacitance film of a capacitor of its memory cell. A dielectric capacitance film used for a capacitor of a DRAM is required to have high uniformity of film thickness and an excellent step coverage.
According to a first aspect of the present invention, there is provided a manufacturing method for a semiconductor device, including:
forming a silicon film on or above a semiconductor substrate, a surface of the silicon film having a first polycrystalline silicon film having mushroom or hemisphere-shaped crystal grains; and
forming a Ta2O5 film on the silicon film at a pressure of 40 Pa or lower and at a temperature of 480xc2x0 C. or lower, using a gas obtained by vaporizing Ta(OC2H5)5 as a tantalum source gas.
According to a second aspect of the present invention, there is provided a manufacturing method for a semiconductor device, including:
forming an undulating film having a surface with concave-convex structure on or above a semiconductor substrate; and
forming a Ta2O5 film on the undulating film at a pressure of 40 Pa or lower and at a temperature of 480xc2x0 C. or lower, using a gas obtained by vaporizing Ta(OC2H5)5 as a tantalum source gas.